The rising incidence of Autism Spectrum Disorders (ASD) challenges researchers to develop novel intervention techniques for children with ASD. Nevertheless, the majority of the research on ASD interventions is focused on traditional and contemporary Applied Behavioral Analysis approaches that target a child's language, cognitive, and preacademic skills. These approaches typically require a child with ASD to engage in intensive 1:1 intervention for 30-40 hours per week. In contrast, administering robot child interactions as an intervention technique may be a significant innovation for various reasons. A robot could serve as an adjunct to a clinician to administer components of an assessment or treatment protocol with some level of standardization and may assist in the data collection process. The programmability of a robot allows us to systematically increase the complexity of social interactions within treatment. Evidence also suggests that children with ASD enjoy interacting with robots due to their simple and predictable behaviors. Most of all, robots are embodied beings that encourage a child with ASD to engage in whole body interactions involving imitation, turn taking, and joint attention bids. Aims: The overall goal of this research is to develop novel intervention techniques for children diagnosed with ASD. Specifically, the proposed project will examine the efficacy of robot child interactions for enhancing social, communication, and perceptuo-motor skills of children with high and low functioning ASD. Our preliminary data on typically developing (TD) children who underwent short-term training with a humanoid robot suggested that all children enjoyed interacting with the robot. The young children performed behaviors such as looking at the robot, greeting the robot, and talking to the robot. They also imitated the complex limb movements performed by the robot. In terms of non-verbal communication, they engaged in turn taking and joint attention behaviors with their teachers and peers. In the proposed project, we have two phases of study. In the first R21 phase we examine robot child interactions in three different projects: a) interactions of TD children between 4 and 8 years of age during short-term training, b) interactions of the same group during interpersonal synchrony tasks, c) Robotic systems development and d) a 5-week intervention for children with ASD using a single subject design. In the R33 phase, we conduct a group design study in which 12 children with ASD between 4 and 8 years of age will receive a 10-week robot child interaction protocol and be compared to a control group of children with ASD. Pre- and post-training assessments will include the PDD- Behavioral Inventory, Movement-ABC, and the Florida Apraxia Battery. We expect the children in the training group to demonstrate advances general social communication measures as well as specific improvements in imitation, nonverbal communication, as well as motor coordination during robot-child interactions. Overall, robot based social intervention is an uncharted, promising intervention tool for enhancing social, communication and motor skills in children with ASD.